Leaf wax alcohols inCoincya (Brassicaceae)

Free and ester alcohol compositions have been determined for leaf waxes in ten taxa belonging to the genusCoincya (Brassicaceae) on the Iberian Peninsula (Spain and Portugal). Size of leaf wax alcohols in the genusCoincya varies between 20 and 31 carbon atoms. This series is dominated by alcohols with an even number of carbon atoms. The most abundant alcohols are C₂₄, C₂₆ and C₂₈ among even and C₂₅, C₂₇ and C₂₉ among odd alcohols, both in free alcohols and in wax esters.     

Comparison of some commercial waxes by gas liquid chromatography

Volatile components (hydrocarbons, monoesters, free acids as methyl esters and free alcohols as acetates) of seven unhydrolyzed commercial waxes-ouricury, carnauba, Chinese insect, lac, esparto, candelilla and Japan wax—have been analyzed and compared by gas liquid chromatography. Though appreciable portions of the waxes were nonvolatile, the results were sufficient to distinguish the seven waxes completely. Methanolysis products were analyzed directly by gas liquid chromatography, and the results agreed with those previously obtained for hydrolysis products of these waxes. Ouricury wax gave 18% C₂₄−C₃₄ αω-diols and 4% C₂₄−C₃₂ ω-hydroxy acids, in addition to 28% C₂₀−C₃₂ aciods and 17% C₂₂−C₃₄ alcohols, on methanolysis. NRCC No. 13387.     

Cuticular lipids of insects: V. Cuticular wax esters of secondary alcohols from the grasshoppersMelanoplus packardii andMelanoplus sanguinipes

Wax esters of secondary alcohols constitute 18–20% of the cuticular lipid extract ofMelanoplus packardii and 26–31% of the cuticular lipids ofMelanoplus sanguinipes. The total number of carbons in the wax esters range from 37–54 with 41 predominating in both species. The fatty acids ofM. packardii wax esters are 16∶0, 18∶0, 14∶0, 20∶0 and 12∶0 in decreasing quantity. The fatty acids ofM. sanguinipes wax esters are 18∶0, 20∶0, 16∶0 22∶0, 14∶0, 19∶0 and 17∶0 in decreasing quantity. The secondary alcohols from the wax esters ofM. packardii are C₂₅, C₂₃ and C₂₇ in decreasing quantity, and the secondary alcohols of theM. sanguinipes are C₂₃, C₂₅, C₂₁, C₂₇, C₂₄, C₂₂ and C₂₆ in decreasing quantity. Each secondary alcohol consists of two to four isomers with the hydroxyl group located near the center of the chain. Montana Agriculture Experiment Station, Journal Series No. 332.     

Molecular analysis of intact preen waxes of Calidris canutus (Aves: Scolopacidae) by gas chromatography/mass spectrometry

The intact preen wax esters of the red knot Calidris canutus were studied with gas chromatography/mass spectrometry (GC/MS) and GC/MS/MS. In this latter technique, transitions from the molecular ion to fragment ions representing the fatty acid moiety of the wax esters were measured, providing additional resolution to the analysis of wax esters. The C₂₁−C₃₂ wax esters are composed of complex mixtures of hundreds of individual isomers. The odd carbon-numbered wax esters are predominantly composed of even carbon-numbered n-alcohols (C₁₄, C₁₆, and C₁₈) esterified predominantly with odd carbon-numbered 2-methyl fatty acids (C₇, C₉, C₁₁, and C₁₃), resulting in relatively simple distributions. The even carbon-numbered wax esters show a far more complex distribution due to a number of factors: (i) Their n-alcohol moieties are not dominated by even carbon-numbered n-alcohol moieties are not dominated by even carbon-numbered n-alcohols esterified with odd carbon-numbered 2-methyl fatty acids, but odd and even carbon-numbered n-alcohols participate in approximately equal amounts; (ii) odd carbon-numbered methyl-branched alcohols participate abundantly in these wax ester clusters; and (iii) with increasing molecular weight, various isomers of the 2,6-, 2,8-, and 2,10-dimethyl branched fatty acids also participate in the even carbon-numbered wax esters. The data demonstrate that there is a clear biosynthetic control on the wax ester composition although the reasons for the complex chemistry of the waxes are not yet understood.     

Mass spectrometric analysis of the fatty acids and nonsaponifiable lipids ofEimeria tenella oocysts

The fatty acids and nonsaponifiable lipids ofEimeria tenella oocysts were analyzed by gas liquid chromatography and combined gas liquid chromatographymass spectrometry. The fatty acids detected were identified as C_14∶0, C_16∶0, C_16∶1, C_18∶0, C_18∶1, and C_18∶2. Though the wt of the fatty acid fraction decreased during sporulation from 91 μg per 10⁶ oocysts to 47 μg per 10⁶ oocysts, the relative amounts of these fatty acids did not change appreciably. The nonsaponifiable lipids ofE. tenella consisted of cholesterol and unbranched primary alcohols of 22, 24, 26, 28, 30, and 32 carbons. Mass fragmentography demonstrated that each species of alcohol consisted of saturated and monounsaturated derivatives. Trimethylsilyl ethers of fatty alcohols were found to offer several important advantages over free alcohols for mass spectrometric characterization. Before sporulation, most fatty alcohols were in the oocyst wall. During sporulation, the wt of the nonsaponifiable lipids increased from 16 μg per 10⁶ oocysts of 44 μg per 10⁶ oocysts due largely to synthesis of C₂₄ and C₂₆ alcohols. The newly synthesized fatty alcohols were not deposited in the oocyst wall.     

Gas chromatographic identification of fatty acids,fatty alcohols,and hydrocarbons ofHibiscus rosa-sinensis leaves

Hibiscus rosa-sinensis leaves (family Malvaceae) were analyzed for their fatty acid, fatty alcohol, and hydrocarbon contents. Wax hydrocarbons ranging from C₁₆ to C₃₂ with C₂₃, C₂₅, C₂₇, and C₃₁ as major components and wax alcohols between C₂₁ and C₃₀ with C₂₆, iso-C₂₈, and iso-C₃₀ as major components were found to be present in the petroleum ether fraction of the leaves. Fatty acids ranging from C₈ to C₂₈ with C₈, C₁₂, C₁₄, C₁₆, and C_18:2 as major components were found in the combined form. Two cyclic acids, sterculic and malvalic, have also been identified.     

Fatty acids,fatty alcohols,wax esters,and methyl esters fromCrambe abyssinica andLunaria annua seed oils

Crambe abyssinica andLunaria annua, members of the Cruciferae family, have seed oil glycerides containing ca. 55–65% of C₂₂ and C₂₄ unsaturated fatty acids. Fatty acids were prepared by saponification; fatty alcohols, by sodium reduction of glycerides; liquid wax esters, byp-toluenesulfonic acid-catalyzed reaction of fatty acids with fatty alcohols; and methyl esters, by reaction of fatty acids with diazomethane. Solid hydrogenated glyceride oils and wax esters were compared with several commercial waxes. Chemical and physical constants were determined for the seed oils and their derivatives. Position of unsaturation in theCrambe fatty acids was determined by gas chromatographic analysis of the permanganate-periodate degradation products. The major dicarboxylic acid was brassylic (C₁₃), proving the docosenoic acid to be erucic. Presented in part at the AOCS meeting in New Orleans, La., 1962. A laboratory of the No. Utiliz. Res. & Dev. Div., ARS, U.S.D.A.     

Gas chromatographic identification of fatty acids,fatty alcohols,and hydrocarbons ofConvolvulus pluricaulis (chois)

Convolvulus pluricaulis (Chois) (Family: Convolvulaceae) (Hindi: Shankhapushpi), widely grown in the northern part of India, was analyzed for its fatty acids and waxy constituents. Straight chain hydrocarbons (C₂₂–C₃₃), fatty acids (C₁₄–C₂₈), and fatty alcohols (C₂₄–C₃₂) were found in the whole plant 95% aqueous ethanol extract. Hydrocarbons (C₂₇, C₃₁, and C₃₃), fatty acids (C₁₄, C₁₆, and C_18:2), and alcohols (C₂₆, iso-C₂₈, iso-C₃₀, and C₃₂) were the major components.     

Surface Composition of Myrmecophilic Plants: Cuticular Wax and Glandular Trichomes on Leaves of <Emphasis Type="Italic">Macaranga tanarius</Emphasis>

Primary plant surfaces, covered with cuticles consisting of cutin and waxes, are important substrates for interaction with insects. The composition of leaf surfaces of the myrmecophilic plant Macaranga tanarius was studied. The prenylated flavanone nymphaeol-C was identified in surface extracts and was localized exclusively in glandular trichomes on the abaxial leaf side. The epidermal pavement cells surrounding these trichomes were covered with a smooth film of epicuticular wax from which few small wax crystals protruded. The epicuticular wax amounted to approximately 8 μg cm⁻², corresponding to 85% of the wax load on the adaxial as well as the abaxial leaf sides. The epicuticular wax mixtures from both leaf surfaces contained more than 70% primary alcohols, 14% fatty acids, 2% aldehydes, and traces of alkyl acetates, with chain lengths ranging from C₂₀ to C₃₈. In contrast, the intracuticular wax layer was largely dominated by triterpenoid alcohols α-amyrin, β-amyrin, and lupeol. Consequently, these characteristic compounds are not available for direct contact with insects on the plant surface.     

Leaf wax of oats

Leaf wax of oats (Kelsey variety) consists of hydrocarbons (5%), esters (10%), free alcohols (45%), free acids (2.5%), β-diketone (5.5%), hydroxy-β-diketones (2.5%), and unidentified (29%). Wax on leaf blades contains more free alcohols than wax on leaf sheaths, and wax on the flag leaf sheath contains more β-diketone than wax on the rest of the plant. Principal hydrocarbons are C₂₉, C₃₁, and C₃₃. The esters, mainly C₄₄–C₄₈ and C₅₂, are probably C₁₈–C₂₂ and C₂₆ esters of hexacosanol. Free alcohols are almost entirely hexacosanol. The β-diketone is hentriacontane-14, 16-dione. Hydroxy β-diketones are a mixture of 5-, 6- and 7-hydroxyhentriacontane-14, 16-diones in the proportions 58∶35∶7. The wax also contains a small amount (0.5%) of 1,16-hexacosanediol. IRCC No. 13472.     

Wax constituents of the winterizer press cake of soybean oil

Summary Wax from the winterizing press cake of soybean oil contains approximately 10 percent free alcohol in addition to true wax. No free acids and apparently no hydrocarbons are present. The principal alcohols range from C₃₂ to below C₂₈, while the acids have an average chain length of approximately 22 carbon atoms. The wax amounts to not more than 0.002 percent of the original oil. Presented before American Oil Chemists’ Society Meeting, Chicago, Illinos, October 2–4, 1940. Now associated with Northern Regional Research Laboratory, Peoria, Illinois. A cooperative organization participated in by the Bureaus of Agricultural Chemistry and Engineering and Plant Industry of the U. S. Department of Agriculture, and the Agricultural Experiment Stations of the North Central States of Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota, and Wisconsin.     

Isolation and identification of constituents of Jasminum auriculatum (Vahl) leaves

Jasminum auriculatum (Vahl) (family: Malvaceae) widely grown in India was analysed for its fatty acids and waxy constituents. Straight-chain hydrocarbons (C₂₀-C₃₄), fatty acids (C₁₄-C₂₃) and fatty alcohols (C₂₁-C₃₂) were found in the 95% aqueous ethanol extract of the leaves of the plant. Malvalic acid was the only cyclic acid identified. Hydrocarbons (C₂₉ and C₃₁), fatty acids (C₁₆, C₁₈, C_18:1, C_18:2, C_18:3 and C₂₂) and fatty alcohols (iso-C₂₆, C₂₈ and C₃₀) were the major components. Four polyalcohols, namely D-mannitol, xylitol, inositol and sorbitol, have also been found in the alcoholic extract of the leaves.     

Composition of the surface lipids of pea leaves (Pisum sativum)

Surface lipid of pea leaves (Pisum sativum var. Frosty) was analyzed with column, thin layer and gas liquid chromatography in conjunction with mass spectrometry and infrared spectroscopy. It contained 42%n-hentriacontane and 7.3%n-hentriacontan-16-ol. About 5% was wax esters, C₄₀–C₅₀ consisting of primarily C₂₆ and C₂₈ alcohols and C₁₆–C₂₂ acids. Almost 5% was aldehydes, mainly C₂₆ and C₂₈. Primary alcohols, chiefly C₂₆ and C₂₈, made up 20% of the surface lipid.     

Melting points of synthetic wax esters

Saturated, monoenoic and dienoic wax esters, C₂₆−C₄₀, have been synthesized from even-numbered fatty alcohols and acids. In homologous series of saturated esters, the increments of melting points follow a regular trend except for those esters which have an acid moiety two carbon atoms shorter than the alcohol moiety. These wax esters have melting points higher than interpolation would predict. Monoenoic wax esters with the double bond in the alcohol chain have melting points about 10 C higher than their isomers with the double bond in the acid chain.     

Chemical composition of the wax secreted by a scale insect (Ceroplastes pseudoceriferus Green)

The wax material in the secretion of a scale insect,Ceroplastes pseudoceriferus Green was analyzed chemically with special interest to the composition of higher fatty acids and higher alcohols. The wax consists of 34.2% fatty acids, 27.1% unsaponifiable matter and 29.5% resin acids. The fatty acids were found to be a complex mixture of 15 normal acids ranging from C₈ to C₃₂. Of these, octacosanoic, triacontanoic and dotriacontanoic acids comprise over 30% of the wax. Presence of relatively large amount of unsaturated fatty acids of the C₁₈ series (2.8% of the wax) is of particular interest. From the unsaponifiable fraction, only one saturated straight chain aleohol, bexacosanol, was detected (2.7% of the original wax). The other unsaponifiable matter was considered to be cyclic or branched carbon chain, and consisted of at least 12 to 20 compounds. The resin acid fraction was also found to be a complex mixture of at least 13 to 14 components.     

Studies of jasmine wax: I. Physical properties and chemical composition

Jasmine wax was fractionated using thin layer chromatography. Six fractions were isolated, purified and identified using combined gas liquid chromatography and mass spectrometry. Infrared spectra were adopted for the chemical structure confirmation of each fraction. The fractions were 49.44% hydrocarbons, 15.73% esters, 3.49% aldehydes and ketones, 7.91% primary fatty alcohols, 8.31% free fatty acids and 8.99% was considered origin. The hydrocarbon fraction was found to consist mainly of saturated chains with C₂₉, C₃₁ and C₂₇ the most predominant. The aldehyde fraction was characterized by straight chains with even numbers of carbon atoms ranging between C₁₀ and C₂₈, whereas the ketone fraction was found to contain a longer chain structure, i.e., C₃₆. However, the C = O was found to be at the C₈ and C₁₁ positions. Free primary alcohols were found to occur in short chains, indicating their existence in the liquid phase, whereas the free fatty acids were found in long chains and were more likely in the solid phase.     

Neutral lipids of chickpea flour and protein isolates

The neutral lipids composition of defatted chickpea flour and two types of protein isolates has been studied. The main compounds in neutral lipids are triacylglycerols, free fatty acids, and diacylglycerols. Other compounds present are wax esters, free fatty alcohols, and free sterols. The main fatty acids in neutral lipids are C_18:2 and C_18:1 among the unsaturated, and C_16:0 and C_18:0 among the saturated acids. Free and esterified alcohols range from C_16:0 to C_28:0, the majority being those with an even number of carbon atoms. Sterols observed are β-sito-sterol, campesterol, stigmasterol, and δ-5-avenasterol. Triacyl-glycerols are partially hydrolyzed, and the amounts of unsaturated sterols and unsaturated fatty acids are reduced as a result of the chemical treatment during production of the protein isolates.     

Properties, composition, and analysis of grain sorghum wax

Grain sorghum wax has been judged to be a potential source of natural wax with properties similar to carnauba wax. Approximately 0.16–0.3% (w/w) wax can be extracted from grain sorghum depending on the efficiency of the organic solvents. Although the melting points of carnauba wax and sorghum wax are similar, i.e., 78–86 and 77–85°C, respectively, they differ in acid values, i.e., 2–10 and 10–16, respectively, and saponification numbers, i.e., 77–95 and 16–49, respectively. Improved knowledge of the properties, composition, and analysis of grain sorghum wax would assist in efforts for industrial application of this product. Major components of sorghum wax are hydrocarbons, wax esters, aldehydes, free fatty alcohols, and FFA. The hydrocarbons consist mainly of C₂₇ and C₂₉, and the aldehydes, alcohols, and acids are mainly C₂₈ and C₃₀. The wax esters are mostly esters of C₂₈ and C₃₀ alcohols and acids.     

Sperm whale oil analysis by gas chromatography and mass spectrometry

Gas liquid chromatography of winterized sperm oil showed that its wax esters with even carbon numbers range from C₂₄ to C₄₂ and are present in quantities resembling a normal distribution curve with C₃₄ as the mean. Between these even-numbered wax esters, ones with odd chain lengths were eluted. Triglycerides, similarly present in a normal distribution pattern, ranged from C₄₂ to C₅₈ and also included traces of odd chain species. The component acids and alcohols were analyzed by gas chromatography-mass spectrometry, and double bond positions in the monoenoid components were established. Branched chain and odd chain constituents, both saturated and unsaturated, were detected among both alcohols and acids. These moieties, when combined with those having even chains, are responsible for the wax esters and triglycerides with odd carbon numbers. ARS, USDA.     

Studies of waxes. VI. The n-acids of carnauba wax

Summary The proportion of normal acids among the acids of carnauba wax has been found, by a chromatographic separation method, to be 38%. The normal acid mixture has been separated into its components by amplified distillation of the methyl esters, which revealed the presence of the acids of even carbon number from C₁₈ to C₃₀. The acids were identified by their melting points, long crystal spacings, and crystal habit. An estimate of their relative amounts is as follows: C₁₈, 3%; C₂₀, 11.5%; C₂₂, 9%; C₂₄, 30%; C₂₆, 12%; C₂₈, 16.5%; C₃₀, 7%. Part V of this series: The Aliphatic Alcohols of Wool Wax, by K. E. Murray and R. Schoenfeld, J. Am. Oil Chem. Soc.,29; 416–420 (1952).